Strategy dismantled
Ms. Thomas-Graham, 42, was president-CEO at CNBC for four years before being replaced and made chairman in February. Since then, Ms. Thomas-Graham has watched her successor, Mark Hoffman, dismantle her programming strategy of running entertainment talk shows during prime time.

As chairman, Ms. Thomas-Graham was to work on “potential brand extensions” and planning initiatives. That role will not be replaced, a CNBC spokeswoman said.

Ms. Thomas-Graham was not immediately available for comment. In a statement issued by NBC Universal this morning announcing her departure, Ms. Thomas-Graham said, "I am proud of all that we have accomplished as a team.” Previously, she was president-CEO of CNBC.com. She joined NBC in 1999 from management consultant McKinsey & Co.

New programming
Mr. Hoffman has replaced many of the shows commissioned under Ms. Thomas-Graham, including Topic A With Tina Brown, the former Talk and New Yorker editor, and McEnroe, hosted by tennis star John McEnroe. One general interest talk show, The Big Idea, hosted by advertising agency CEO Donny Deutsch, remains on the schedule. Mr. Hoffman wants to focus evening hours on business shows, and has had one recent success with Mad Money, a stock-touting series hosted by trader James Cramer. The channel has also talkied to advertisers about sponsoring a new investment show that is in the works.